The present invention relates to a device and method for collecting blood and other body fluids, such as urine, saliva, cerebral spinal fluid, etc., and tissues from individuals and/or animals in forensic, clinical, paternity, veterinary or other types of sample testing to uniquely mark the specimen to be studied, so that any contamination and/or tampering will be readily detectable. This method may also be applied to the marking of other samples, such as those derived from plants, animals, or non-biologic origins. The markers of the present invention may also be used as controls in evaluating laboratory procedures, such as sample handling, and/or for the testing of forensic, clinical, paternity, veterinary or other laboratories or personnel for certification, proficiency testing, or accreditation purposes.
Samples are collected for analysis by many methods for many different purposes, including to establish identity by DNA analysis. Misidentification and cross-contamination of samples are two problems that must be eliminated to ensure the validity of any test results. The handling of samples for forensic identification has caused problems for investigators and laboratories analyzing crime scene evidence and suspect samples. Defense attorneys are frequently successful in acquitting their clients if they can impugn the forensic evidence on the basis of inadvertent or deliberate contamination of the crime scene evidence with material (blood or DNA) obtained from a suspect (i.e., the defendant). The case of O. J. Simpson vs. State of California is a notorious example where the integrity of the DNA evidence was questioned.
There are approximately 3.3 billion DNA base pairs in the human genome, and many regions vary between individuals, thus making the identification of a unique individual possible. DNA regions are chosen for forensic analysis on the basis of specificity to humans and degree of polymorphism, that is the polymorphic regions are likely to differ between randomly chosen individuals.
There are many DNA sequences from other species which are not present in human DNA which should not interfere with the analysis of human genetic polymorphism. These include bacterial genes (such as neomycin and other antibiotic resistance genes), phage, yeast, non-primate animal and plant genes. The sequence of many of these genes are known and they are relatively easy to produce and test for lack of cross-reactivity in current forensic or other tests. Additionally, completely artificial DNA sequences can be made which have no human analogs. These sequences can be used to mark samples at the time of collection, so that any subsequent cross-contamination can be determined.
Recently, there has been mounting pressure for laboratories that handle body fluid and tissue samples to submit to certification, proficiency testing and/or accreditation, to ensure that a particular laboratory is professionally run and meets with certain national standards. Markers such as those illustrated above, and/or non-nucleic acid markers such as proteins or peptides, chemicals or elements, can be used as controls in evaluating laboratory procedures, such as sample handling, for purposes of such certification, proficiency testing and/or accreditation.
There exist numerous tamper-resistant devices for collecting samples in the art. For example, U.S. Pat. No. 4,873,193 is directed to a method and apparatus for the collection and preservation of fluid biological evidence. The apparatus comprises a specimen vial and lid, with the lid having an adhesive coated disk inserted therein. The lid is initially inverted on the rim of the specimen vial and is encased in a tamper-evident plastic wrapper. The specimen vial and lid, encased in the tamper evident wrapper, are sealed within an outer container with a second tamper evident plastic wrapper. The container exists in a tamper-evidencing state prior to the product being placed therein. This first tamper-evidencing seal is broken, the item of evidence is placed therein, and the container is thereafter resealed once the item has been placed in the container. A new tamper-evident seal is thus created. There is no disclosure in the ""193 patent of adding markers to the specimen vial to prevent tampering.
There also exist numerous methods and kits for tagging substances. For example, U.S. Pat. Nos. 4,953,562, 5,039,616 and 5,179,027 are all directed to tagging for the purposes of preventing the introduction of false specimens in urinalysis. These patents are directed to identifying the source of urine samples collected for biochemical analysis where there is a potential for laboratory error or deceptive substitution of one urine specimen for another. In these methods of urine specimen identification, the individual whose urine is to be tested consumes one or more formulations containing one or more harmless identifying substances that can be rapidly absorbed by the body and will quickly appear in the urine. The collected urine is later analyzed for the presence of these substances, thereby determining the source of the specimen and detecting any error or deceptive substitution thereof. There is no disclosure in these patents of adding markers to the collection device before the urine sample is added thereto. Instead, all of the markers are first consumed by the individual who is to provide the sample. The urine sample is thus xe2x80x9ctaggedxe2x80x9d before it is collected.
U.S. Pat. No. 4,441,943 is directed to a method of tagging a substance to allow for the subsequent identification thereof by incorporating a polypeptide into the substance. Example substances to be tagged include explosive compositions or oil. The ""943 patent discloses incorporating tags into the substance to be tagged and thereafter releasing the tagged substances into their normal environments of use. After an accident or illegal activity involving the tagged substances, the tagged substances are collected, and the tags are examined for information on their origination. There is no disclosure of a sample collection device having markers associated with the device.
U.S. Pat. No. 5,451,505 is directed to methods for tagging and tracing materials using nucleic acids as taggants. More particularly, the invention provides for a method of monitoring the presence of a substance by tagging the substance with a nucleic acid, collecting the substance and detecting the nucleic acid. The materials or substances contemplated for tagging include air pollutants, oils, aromatic compounds, explosive compositions, foodstuffs, medicaments, inks, paper goods and paint products. There is no disclosure of a sample collection device having markers associated therewith.
The present invention provides a sample collection device and method which minimizes the risk of undetected cross-contamination due to error or fraud. A method of and a device for marking a sample from a given individual, animal, plant or non-biologic substance from the moment of sample collection is provided (i.e., identifying that a particular sample came from a given individual, animal, plant or non-biologic substance), as well as a method for determining the integrity of a sample (i.e., the presence or absence of extraneous markers, which would signal contamination, or the determination of sample deterioration). The present device and method provide a means for determining whether or not cross-contamination has occurred at any subsequent point in the handling of sample materials.
Specifically, the present invention includes a device suitable for marking a collected sample, comprising:
collecting means for collecting the sample; and
at least one detectable marker which is associated with at least a portion of the collecting means, wherein the at least one detectable marker is contactable with the sample upon collection of the sample to mark the collected sample upon contact of the sample with the at least a portion of the collecting means having the at least one detectable marker associated therewith, and wherein the at least one detectable marker is other than a component which is present in the sample before collection and is inert to any component present in the sample before collection.
Also included in the invention is a kit suitable for marking a body fluid evidence sample, comprising the device as described above, means for identifying at least one of the identity and the amount of the at least one detectable marker and tamper-evident sealing means for tamper-evident sealing of the collecting means and the at least one detectable marker.
The invention further includes a method for marking a sample, comprising collecting the sample using a collection device having at least one detectable marker which is associated with at least a portion of the collecting device, wherein the at least one detectable marker is other than a component which is present in the sample before collection and is inert to any component present in the sample before collection, and causing the sample to contact the at least one detectable marker to pass at least a portion of the at least one detectable marker into the sample to mark the sample.
The invention also includes a method for determining the integrity of a marked sample, comprising:
(a) providing a sample which is marked as recited above;
(b) thereafter detecting at least one of an identity and an amount of the at least one detectable marker to provide a result; and
(c) comparing the result from step (b) with known information as to at least one of the identity and the amount of the at least one detectable marker to determine the integrity of the marked sample.
The invention further includes a method for using at least one detectable marker to determine the integrity of a marked sample in a certification or accreditation procedure, the method comprising:
(a) providing a sample comprising a test material and at least one detectable marker to a test laboratory for testing the test material, wherein the at least one detectable marker is present in the sample in at least one of an identity and an amount which is unknown to the test laboratory;
(b) obtaining at least a portion of the sample from step (a) after the test material has been tested by the test laboratory;
(c) thereafter detecting at least one of the identity and the amount of the at least one detectable marker to provide a result; and
(d) comparing the result from step (c) with known information as to at least one of the identity and the amount of the at least one detectable marker to determine the integrity of the marked sample.
The use of at least one detectable marker in laboratory testing to ensure sample integrity and as a control in evaluating laboratory procedures is also included, along with the use of at least one detectable marker for the testing of laboratories and/or laboratory personnel for certification, proficiency testing or accreditation purposes.
The invention further includes the use of at least one detectable marker in the manufacture of a device suitable for marking a sample, wherein the at least one detectable marker is other than a component which is already present in the sample and is inert to any component already present in the sample.